Yeast Protein and Uric Acid: What You Should Know About Nucleic Acids
One question comes up again and again about yeast protein: "Will it raise my uric acid?" It is a fair question, and it deserves a careful answer rather than marketing. Here is what the science and regulations actually say.
Why yeast and uric acid are linked
Fast-growing cells like yeast are rich in nucleic acids (RNA and DNA). When you digest nucleic acids, the purines in them are broken down into uric acid. High uric acid in the blood can lead to gout and kidney stones in susceptible people. Whole yeast can contain a lot of RNA, which is why this became an issue as early as the single-cell protein era of the 1970s (see the history of yeast protein).
Food-grade yeast protein has most RNA removed
Making a food-grade yeast protein isolate includes a step to reduce nucleic acid (see how it is made). Regulators set limits:
- United States: yeast protein under 21 CFR 172.325 must have under 2% nucleic acid.
- China: the 2023 yeast protein standard sets RNA at 2.0 g per 100 g or less.
- Singapore: under 2% for single-cell protein.
An international guideline from the UN's Protein Advisory Group suggests adults keep nucleic acid from single-cell protein to no more than 2 g per day.
What that means per serving
A 30 g serving of yeast protein at 2% nucleic acid contains at most about 0.6 g of nucleic acid, roughly 30% of that daily guideline. Even two servings a day stay within it. That is one reason we suggest one serving a day for most people, and two as a sensible upper limit for healthy adults.
New to yeast protein? Start with the Fizinga Variety Pack: 8 sachets of Cold Coffee and Strawberry, 24 g protein each, so you can try both flavours before buying a 1 kg pack.
What the evidence shows, and what it doesn't
The best related evidence comes from mycoprotein, another microbial protein. In one trial, a high-nucleotide version raised blood uric acid from about 295 to 472 µmol/L, while a low-nucleotide version produced no change. That shows why RNA reduction matters.
However, no human trial has yet measured uric acid after regular intake of yeast protein isolate. So we do not describe yeast protein as "low purine" or "safe for gout". Anyone who does is going beyond the evidence.
Other safety points
- Yeast allergy: rare but real, around 1.4% in the general population and higher in people with other allergies. Some people with mould allergy may also react. Yeast protein is not hypoallergenic.
- Crohn's disease: many people with Crohn's carry antibodies to baker's yeast, so they should check with their doctor.
Who should speak to a doctor first
- People with gout or high uric acid
- People with kidney disease
- Anyone with a yeast or mould allergy
- Pregnant or breastfeeding women
- People with Crohn's disease
- Protein powders are not suitable for infants
For healthy adults at normal servings, yeast protein's safety is well supported by a long history of yeast in food, regulatory approvals and no safety signals in trials. Read more in is fermented yeast protein safe?
How Fizinga fits in
Fizinga Smart Protein uses food-grade fermented yeast protein and recommends one serving a day for most people. Our Unflavoured, Cold Coffee and Strawberry packs carry the advisory statements required for health supplements, and we don't make gout or purine claims.
Frequently asked questions
Does yeast protein increase uric acid?
Food-grade isolates have most nucleic acid removed and must meet limits of about 2%. No human uric acid trial exists for isolates yet, so people with gout should consult a doctor.
Is yeast protein low purine?
That claim is unproven. We don't make it.
How many servings a day are safe?
One serving suits most people; two is a sensible upper limit for healthy adults and keeps nucleic acid within the international guideline.
Is yeast protein hypoallergenic?
No. Yeast allergy exists, and people with yeast or mould allergy should avoid it or seek advice.
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Sources: US 21 CFR 172.325, China's 2023 yeast protein standard, PAG/UNU guidance and published mycoprotein and allergy studies, as reviewed in Fizinga's 2026 research white paper. This article is for general information and is not medical advice.
